1. Field of the Invention
The present invention generally relates to a gas hood for a gas regulator. More particularly, the present invention relates to a gas hood that prevents water vapor from condensing on a gas regulator.
2. Description of the Prior Art
Regulator is a critical device in high-pressure gas supply system. When gas is released from a high-pressure gas source (ex. a liquid gas cylinder), the pressure of the gas may be higher than 500 psi (pound per square inch). The gas with such an enormous pressure can't be readily used in most gas processing equipments or process tools. For this reason, the output pipeline of high-pressure gas source should be equipped with gas regulators to lower the pressure of output gas down to a normal level, such as dozens of psi, so that the output gas can be processed or utilized.
Please refer to FIG. 1, which is a cross-sectional view of a gas regulator 100 conventionally used in prior art. As shown in FIG. 1, the gas from a high-pressure gas source (not shown) will be introduced into the gas regulator 100 via an input pipeline 103 and then be extracted after the pressure is reduced via an output pipeline 105. During the gas supplying and pressure reducing steps, the pressure of the gas passing through the gas regulator 100 is dramatically reduced. In the meantime, the temperature of the gas regulator 100 is severely reduced to a level lower than the dew point temperature, due to the Joule-Thomson effect. Therefore, the water vapor 107 will condense on the sidewall 109 and the base 111 of the gas regulator 100. The condensation of water vapor on the gas regulator will inhibit the heat exchanges between the cooled gas regulator 100 and the ambient air. Eventually, the gas regulator will freeze. If the condensing issues and freezing issues of the gas regulator can't be improved, the gas passing through the regulator will be cooled, thereby increasing the density of the gas. This may have severe impact in precise semiconductor processes.
Accordingly, it is still necessary to develop a novel approach to resolve the above-mentioned water vapor condensation issue on gas regulators.